The invention relates to a process as well as an apparatus for the refining of rolling stock as the starting product for chocolate.
In the production of chocolate, the stock comminuted by means of roller frames, such stock containing almost all of the components of the recipes, is still today filled into so-called conching means and is liquefied therein over a period of time of many hours. This process requires very much space for the apparatus elements necessary for carrying it through, and moreover it operates discontinuously, so that it must be regarded as outdated considering today's high state of the automation technique. There has not been a lack of attempts at having the process run off continuously. These attempts ultimately failed on account of the fact that either the modes of conducting the process found were too complicated and, hence, uneconomical, or the result, hence the product quality, have not been satisfactory.
All process techniques in the production of chocolate based on the principle of conching have in common that work is conducted in large, open, temperable containers, in which there are disposed specially designed mechanical built-in structures which in some form circulate the stock. These built-in structures consist of varyingly shaped agitating and kneading members, which serve to bring about as large as possible a surface area of the stock so as to cause an intensive exchange of materials at the boundary surface of product mass/air, and they form as well variously shaped gaps, through which the chocolate mass is pressed. In that way high shearing forces result, which cause the envelopment of the solid particles with cocoa butter, the so-called buttering (oiling), whereby there is attained not only a good flow behaviour but, rather, also a good melting characteristic in the finished chocolate. The increased temperature accelerates the exchange of materials (substances). After a predetermined time of conching, the flavor refining can be considered as concluded.
Substantially undesirable aroma substances are removed from the product through the conching process in a first treatment phase under mild mechanical stress. In a second treatment phase, the buttering required for the glaze is attained through intensified mechanical processing, and the flow behaviour required for the further processing is adjusted. It is decisive in that regard that the entire flavour-developing process conduction, inclusive of the mechanical treatment, for attaining a good flow behaviour be divided up into various processing segments. For example, the raw cocoa mass must be pre-degassed and pre-refined under the addition of water or of specific reaction solutions, and the resultant product roasted in a thin layer and further refined by means of reaction solutions, for example carbohydrates. It has been shown that the simple degassing or roasting of cocoa mass in a thin layer does not suffice in order to allow all necessary materials exchange operations between the components of the cocoa mass and the carbohydrates or also milk components to take place. On the other hand, no purposive reactions can occur between the reaction partners in the conching means, as only random contacts between the reaction partners result in the conching means. Moreover, conching of the type used so far is a discontinuous method and, consequently, is of disadvantage not only for energetic reasons but, rather, also in respect of attaining a uniform product quality.
Furthermore, according to present day recognitions, a pre-degassing of the cocoa mass or a pre-treatment of the milk components is not sufficient to ensure the intended product quality at a later liquification of the product in a conching means or also by way of a continuous method.